Mechanical properties and shape memory effect of 4D printed cellular structure composite with a novel continuous fiber-reinforced printing path

Herein, a printing strategy was proposed and expended, which allows fabricating diverse geometries of cellular continuous fiber-reinforced composites (CFRCs) with fiber distribution and interlacement in the cellular structure uniformly. A class of printed triangle-filled cellular structure composites was prepared to present the detail of the printing strategy. The effects of printing and structural parameters on the mechanical properties, as well as shape memory performance of printed CFRCs, were studied precisely, and thereafter, a Finite Element (FE) model was developed on the basis of the printing path to stimulate and analyze the tensile process. Experimental results showed that introducing only 3.8% fiber content into the composite can significantly improve the tensile strength by more than 300%. An increment of cell length was capable of strengthening tensile features compellingly due to changing orientation and alignment degree of fiber in the structure. By contrast, sizing the cell length and embedding further fiber have represented a reverse pattern against the composite's shape recovery ratio, which witnessed an adverse impact on shape-changing materials. A conclusion was given that the mechanical properties and shape memory effect of the 3D-printed continuous fiber-reinforced composite can be optimized by adjusting the geometric parameters and fiber content. (C) 2020 The Authors. Published by Elsevier Ltd.

Automated summary

A printing strategy for fabricating diverse geometries of cellular continuous fiber-reinforced composites with uniform fiber distribution and interlacement in the structure was proposed and studied. The effects of printing and structural parameters on mechanical properties and shape memory performance were investigated, and a Finite Element model was developed to analyze the tensile process. Adjustment of geometric parameters and fiber content was found to optimize the mechanical properties and shape memory effect of 3D-printed CFRCs.